I've always considered abortion an issue that progressives have generally done a good job of framing.

The "pro-life" framing attempts to create a debate on the value of life, and that is a debate in which abortion rights supporters and the Democratic Party have (rightly) refused to participate. The "pro-choice" terminology reframes the debate in terms of self-ownership and privacy rights. The effectiveness of this is evident in anti-abortion slogans that attempt to dispute the framing directly ("it's a life, not a choice").

Of course, the progressive frame has failed to dominate the issue, but so has the conservative one. The debate has become one between competing frames, which is very different from allowing Republicans to frame the debate and then taking an opposite stance within that framework.